Definition. A metric space is a set X together with a function d (called a metric or distance function) which assigns a real number d (x, y) to every pair x, y X satisfying the properties (or axioms): 1  d (x, y) 0 and d (x, y) = 0 x = y, 2  d (x, y) = d (y, x),
Here are some facts and guidelines about formaldehyde in plywood and OSB that can help you when building a chicken coop: 1  Formaldehyde is used in the binders and resins of some manufactured wood products. 2  Offgassing can be an issue with products containing urea-formaldehyde (UF) resins.
OSB vs. Plywood. While OSB (Oriented Strand Board) is generally cheaper than plywood, it is heavier and not as stiff as plywood and can result in soft squeaky floors under weight. The biggest complaint against OSB is that it doesn't handle moisture very well so it is more suited for indoor use.